Re: [Yaffs] df problem on yaffs2

On Wednesday 16 December 2009 16:36:02 JiSheng Zhang wrote:
> 2009/12/16 JiSheng Zhang <jszhang3@gmail.com>:
> > Hi list,
> >
> > First mount an empty partition, then cp some files to the mnt dir then
> > run "df", and then delete all the files, then run "df" again. df
> > report this time is wrong. It seems that the chunks occupied by
> > unlinked files aren't recycled until needed.
> >
> > Is this a bug or characteristic?

I don't see that problem.

root@linux-dual-head:/opt/y/cvs/yaffs2# mount -t yaffs2 /dev/mtdblock0 /mnt
root@linux-dual-head:/opt/y/cvs/yaffs2# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mtdblock0           65536      1152     64384   2% /mnt
root@linux-dual-head:/opt/y/cvs/yaffs2# cp * /mnt
root@linux-dual-head:/opt/y/cvs/yaffs2# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mtdblock0           65536      5860     59676   9% /mnt
root@linux-dual-head:/opt/y/cvs/yaffs2# rm /mnt/*
root@linux-dual-head:/opt/y/cvs/yaffs2# df
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/mtdblock0           65536      1156     64380   2% /mnt

If you can make a test case then I would like to see it please.

>
> I think I found where the problem was. in revision 1.62 of
> yaffs_guts.c yaffs_ResizeFile(in, 0); is added at the beginning of
> function yaffs_DeleteFile(). Could someone give an explanation?

The Resize was done because this removed the need for SoftDelete. Doing it
this way makes the garbage collection faster.

-- CHarles